More than 49 million people in the UK have received at least one dose of a coronavirus vaccine - part of the biggest inoculation programme the country has ever launched.
With almost nine in 10 of those aged 12 or over having had a single jab, the country is now running an autumn booster campaign.
Who can get a vaccine now?
All those aged 12 and over are now being offered a Covid vaccine.
The vaccine rollout, which launched in winter 2020, began with those considered most vulnerable and later moved down the age groups.
A single vaccine dose is now being offered to all 12 to 17-year-olds in schools across the UK.
The government has launched a booster campaign, with frontline health and social care workers the first to receive a third dose.
Boosters will also be offered to the over-50s and younger adults with certain health conditions.
So far, the UK has approved four vaccines for use: Pfizer-BioNTech, Oxford-AstraZeneca, Moderna and Janssen; three of which require two doses for maximum protection.
Al those aged under 40 are being offered an alternative to the Oxford-AstraZeneca vaccine due to evidence linking it to rare blood clots.
The vaccine currently being used for under-18s in the UK is Pfizer-BioNTech, but the Moderna vaccine has also been authorised for use in children.
Those eligible for boosters will receive one dose of Pfizer or half a dose of Moderna.
There is no vaccine currently approved for use in the under-12s.
How is the rollout going?
So far, more than 49 million people have had a first vaccine dose - about 86% of over-12s. More than 45 million - about 79% of over-12s - have had both doses.
The number of first doses administered each day is now averaging about 33,000 - far below a peak of some 500,000 in mid-March.
An average of about 27,000 second doses are now being given a day.
Progress made in the UK so far means the country continues to be among those with the highest vaccination rates globally - but it has slipped out of the top 10 countries with a population of at least one million.
Vaccination rates have now levelled off in every age group in England apart from 16 and 17-year-olds, as the chart below shows.
The highest rates of vaccination can be seen in the oldest age groups - among the first to be vaccinated.
The aim of the vaccination programme is to protect as many people as possible from serious illness through developing the UK population's immunity against Covid-19.
Data from the Office for National Statistics (ONS) suggests more than nine in 10 adults in the UK now have coronavirus antibodies - which is evidence of a past Covid infection or having received at least one dose of a vaccine.
However, this figure does not tell us how many people are protected from infection or how close we are to reaching herd immunity - the point at which everyone is protected, directly or indirectly, as a result of high immunity levels in the population.
The UK Health Security Agency, which replaced Public Health England, estimates that, up to 24 September, the UK vaccination programme has prevented about 24 million infections, 260,000 hospitalisations and 127,500 deaths.
Has the rollout been even across all areas?
Across the country, there continues to be some variation in the vaccine programme.
Scotland has vaccinated 90% of those aged 12 and over with at least one dose, while Wales has reached 87%, England 85% and Northern Ireland 82%.
Second doses are also being rolled out, with all nations reaching about 80% of over-12s so far.
Across the English regions, the South West has vaccinated 82% of the same age group with at least one dose, while London has reached 64%.
There have also been disparities between ethnic groups and poorer and wealthier areas.
Analysis of NHS records by the OpenSAFELY group - a collaboration between Oxford University and the London School of Hygiene and Tropical Medicine - shows that black people were the least likely to have received a vaccine.
The study was based on more than 20 million patient records in England and covers people not living in care homes. Areas of London are under-represented in the data.
In addition, vaccine take-up in poorer areas is lower than in more affluent areas.
For example, 88% of those aged 50 and over in the poorest areas had been given a vaccine by 6 October, compared with 95% in the most affluent.
Where are the vaccines coming from?
The Pfizer-BioNTech jab - the first to be given the green light last December - is being imported from Puurs, Belgium.
A second vaccine, from Oxford University and AstraZeneca, is being made at a number of sites in Britain. Further doses are expected to come from the Serum Institute of India and the Halix plant in the Dutch city of Leiden.
The third, from Moderna, is coming from sites in Switzerland and Spain, via Belgium, while the Janssen vaccine, due to arrive later this year, is produced in the Netherlands by the Belgian firm, owned by Johnson & Johnson.
The UK is also lined up to receive another vaccine if approved for use.
The jab, manufactured by US firm Novavax, will be made in Stockton-on-Tees in north-east England.
Is there enough vaccine?
The UK had ordered more than 540 million doses of seven of the most promising vaccines, including the four so far approved for use. But the French vaccine maker Valneva says the UK government has scrapped a deal for 100m doses of its vaccine, which is yet to be approved.
An extra 35 million doses of the Pfizer-BioNTech vaccine were ordered in August, on top of another 60 million ordered earlier in the year, as part of the government's plans for a vaccination booster programme.
But it has amended its original order of the Janssen single-dose vaccine from 30 million to 20 million doses, given the "unprecedented scale and pace" of the vaccination programme.
Ministers have also announced an eighth deal with biopharmaceutical company CureVac to develop vaccines against future variants.
It has placed an initial order for 50 million doses to be delivered later this year - if they are required.